Finding the Third Proportional to 17.89 and 42.31

Step by Step Solution

1. Step 1: Write the proportion equation
   17.89 : 42.31 = 42.31 : x
2. Step 2: Convert to fraction form
   17.89/42.31 = 42.31/x
3. Step 3: Cross multiply
   17.89x = 42.31 × 42.31
4. Step 4: Simplify right side
   17.89x = 1,790.51
5. Step 5: Solve for x
   x = 1,790.51/17.89
6. Step 6: Final answer
   x = 100.10